Move skills to repo `ouds-web-skills` and update documentation

[MaxLardenois]

• open a ouds-web-skills repo (https://github.com/Orange-OpenSource/ouds-web-skills)
• push https://github.com/Orange-OpenSource/Orange-Boosted-Bootstrap/tree/v1.5.0-ouds-web/skills in a ouds-web-1.5 folder
• update README, Getting Started and Home
• update wiki https://github.com/Orange-OpenSource/Orange-Boosted-Bootstrap/wiki/Developer-guide#update-provided-skills
• add a README in ouds-web-skills repo
• update release checklist with a new step to publish skills inside a new folder in ouds-web-skills repo

Note: investigate coherence check between skills and current lib version